Phenolic profiling and bioactivity assessment of in vitro propagated Psidium cattleianum Sabine: A promising study

Psidium cattleianum Sabine (strawberry guava) is an evergreen shrub that is grown as a fruiting hedge and has received significant consideration in the food and pharmaceutical disciplines. This study aims to set a promising protocol for in vitro propagation of P. cattleianum, along with profiling the phenolic content of the original plant (OP), induced callus (IC), and regenerated plantlets (RP) extracts, ultimately, evaluating their anti-inflammatory, antioxidant, and anticancer potential. Seeds were treated with commercial bleaching, HCl, and H2O2 to enhance the germination percentage and minimize the contamination percentage. Culturing sterilized leaf explants onto Murashige and Skoog (MS) medium supplemented with benzyl adenine (BA), 2,4-dichloro phenoxy acetic acid, and kinetin showed the best callus induction, while supplementation of MS media with BA, adenine sulfate, naphthalene acetic acid, and gibberellic acid activated regeneration. Augmentation of MS media with indol-3-butyric acid recorded the maximum rooting percentage. Finally, the obtained rooted shoots were successfully acclimatized in sand and peat moss soil. HPLC-MS/MS profiles of OP, RP, and IC showed a variety of phenolic metabolites. IC extract decreased the viability of MCF-7, HepG2, and K-562 cancer cell lines. Also, OP exhibits strong antioxidant activity. P. cattleianum and its RP are profound sources of phenolic compounds promoted for promising applications in the food and pharmaceutical industries.

Chemical and biological characterization of Melaleuca subulata (Cheel) Craven leaves' volatile constituents supported by chemometric analysis and molecular docking

BACKGROUND

The genus Melaleuca (Myrtaceae) comprises dozens of essential oil (EO)-rich species that are appreciated worldwide for their various medicinal values. Additionally, they are renowned in traditional medicine for their antimicrobial, antifungal, and other skin-related activities. The current study investigated the chemical profile and skin-related activities of volatile constituents derived from M. subulata (Cheel) Craven (Synonym Callistemon subulatus) leaves cultivated in Egypt for the first time.

METHODS

The volatile components were extracted using hydrodistillation (HD), headspace (HS), and supercritical fluid (SF). GC/MS and Kovat's retention indices were implemented to identify the volatile compounds, while the variations among the components were assessed using Principal Component Analysis and Hierarchical Cluster Analysis. The radical scavenging activity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and β-carotene assays. Moreover, the anti-aging effect was evaluated using anti-elastase, and anti-collagenase, while the antimicrobial potential was deduced from the agar diffusion and broth microdilution assays. Lastly, the molecular docking study was executed using C-docker protocol in Discovery Studio 4.5 to rationalize the binding affinity with targeted enzymes.

RESULTS

The SF extraction approach offered the highest EO yield, being 0.75%. According to the GC/MS analysis, monoterpene hydrocarbons were the most abundant volatile class in the HD oil sample (54.95%), with α-pinene being the most copious component (35.17%). On the contrary, the HS and SF volatile constituents were pioneered with oxygenated monoterpenes (72.01 and 36.41%) with eucalyptol and isopulegone being the most recognized components, representing 67.75 and 23.46%, respectively. The chemometric analysis showed segregate clustering of the three extraction methods with α-pinene, eucalyptol, and isopulegone serving as the main discriminating phytomarkers. Concerning the bioactivity context, both SF and HD-EOs exhibited antioxidant effects in terms of ORAC and β-carotene bleaching. The HD-EO displayed potent anti-tyrosinase activity, whereas the SF-EO exhibited significant anti-elastase properties. Moreover, SF-EO shows selective activity against gram-positive skin pathogens, especially S. aureus. Ultimately, molecular docking revealed binding scores for the volatile constituents; analogous to those of the docked reference drugs.

CONCLUSIONS

M. subulata leaves constitute bioactive volatile components that may be indorsed as bioactive hits for managing skin aging and infection, though further in vivo studies are recommended.

Phytochemical profile and antimicrobial activity of essential oils from two Syzygium species against selected oral pathogens

BACKGROUND

The genus Syzygium (Myrtaceae) comprises several essential oil-rich species that are utilized traditionally for treating tooth infections and toothache. The current study aimed to extract essential oils (EOs) from the leaves of Syzygium samarangense and Syzygium malaccense cultivated in Egypt for the first time and screen their antimicrobial potential against oral-related pathogens.

METHODS

The intended EOs were extracted using hydrodistillation (HD) by boiling fresh leaves with distilled water; supercritical fluid (SF) by extracting the dried leaves using supercritical CO2 at 40 °C and 150 bar; and the headspace (HS) in which the fresh leaves were heated in a glass vial and the vaporized aroma were analyzed. The volatile constituents were analyzed using GC/MS and identified by comparing the experimental Kovats' retention indices with the literature. The antimicrobial activity was assessed against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Candida albicans using agar diffusion, microwell dilution, and biofilm formation assays. Statistical significance (p < 0.05) was determined by applying one-way ANOVA and Duncan's post hoc test.

RESULTS

The yield of the extracted EOs differs between the applied methods, and the SF approach harvested the maximum (0.52-0.46%). The GC-MS analysis of SF EOs revealed a discrepancy between the two species. Since S. malaccense showed an abundance of hydrocarbons represented mainly by squalene (60.60%), S. samarangense was deemed to have oxygenated sesquiterpenes exemplified in globulol (52.09%). On the other side, the HD and HS EOs were sequentially comparable, while differed in the percentage of their majors. γ-terpinene (33.06%) pioneered the HS-derived aroma of S. malaccense, while S. samarangense was abundant with α-pinene (30.18%). Concurrently, the HD EOs of S. malaccense and S. samarangense were commonly denoted by caryophyllene oxide (8.19%-18.48%), p-cymene (16.02%- 19.50%), and γ-terpinene (12.20%-17.84). Ultimately, both species EOs exhibited broad-spectrum antimicrobial potential, although the HD EO was more potent than the SF EO. The HD EOs of both species potently inhibited the growth of E. coli (MIC 3.75 µL/mL) and suppressed C. albicans biofilm formation by 83.43 and 87.27%, respectively. The SF-EOs efficiently suppressed the biofilm formation of Gram-positive bacteria by 76.45%-82.95%.

CONCLUSION

EOs extracted from both species by different methods possessed a unique blend of volatile components with broad-spectrum antimicrobial activity. They were promoted as bioactive hits for controlling oral infections, however further investigations concerning their safety in clinical settings are needed.

Bioactive metabolites identified from Aspergillus terreus derived from soil

Aspergillus terreus has been reported to produce many bioactive metabolites that possess potential activities including anti-inflammatory, cytotoxic, and antimicrobial activities. In the present study, we report the isolation and identification of A. terreus from a collected soil sample. The metabolites existing in the microbial ethyl acetate extract were tentatively identified by HPLC/MS and chemically categorized into alkaloids, terpenoids, polyketides, γ-butyrolactones, quinones, and peptides. In addition, a new triglyceride (1) and a diketopiperazine derivative namely asterrine (4), together with two known butyrolactone (2-3) were purified from the extract. The chemical skeleton of the purified compounds was established by comprehensive analysis of their ESI/MS, 1 and 2D-NMR data. The extract and compounds 3,4 exhibited a strong inhibitory activity for the binding of ACE2 to SARS-CoV-2 spike-protein receptor with IC50 7.4, 9.5, and 8.5 µg/mL, respectively. In addition, the extract, 1 and 2 displayed a potent anti-inflammatory effect with IC50 51.31 and 37.25 pg/mL (Il-6) and 87.97, 68.22 pg/mL (TNF-α), respectively, in comparison to LPS control. In addition, the extract and compound 4 displayed an antimicrobial effect towards S. aureus by MIC 62.5 and 125 μg/mL, while the extract exhibited a potent effect against C. albicans (MIC of 125 μg/mL). Collectively, our data introduce novel bioactivities for the secondary metabolites produced by the terrestrial fungus Aspergillus terreus.

Corrigendum: Essential oils of Psidium cattleianum Sabine leaves and flowers: anti-inflammatory and cytotoxic activities

[This corrects the article DOI: 10.3389/fchem.2023.1120432.].

Quercus coccinea Münchh leaves polyphenols: Appraisal acute lung injury induced by lipopolysaccharide in mice

Genus Quercus is a well-known source for its polyphenolic content and important biological activity. Plants belonging to the Quercus genus were traditionally used in asthma, inflammatory diseases, wound healing, acute diarrhea, and hemorrhoid. Our work intended to study the polyphenolic profile of the Q. coccinea (QC) leaves and to assess the protective activity of its 80% aqueous methanol extract (AME) against lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Together, the potential molecular mechanism was investigated. Nineteen polyphenolic compounds (1-18), including tannins, flavone, and flavonol glycosides. Phenolic acids and aglycones were purified and identified from the AME of QC leaves. Treatment with AME of QC showed an anti-inflammatory effect evidenced by a remarkable decline in the count of white blood cells and neutrophils which was in harmony with decreasing the levels of high mobility group box-1, nuclear factor kappa B, tumor necrosis factor-α, and interleukin 1 beta. In addition, the antioxidant activity of QC was documented through the significant reduction in malondialdehyde level and elevation of reduced glutathione level and superoxide dismutase activity. Furthermore, the mechanism involved in the pulmonary protective effect of QC involved the downregulation of the TLR4/MyD88 pathway. The AME of QC showed a protective effect against LPS-induced ALI through the powerful anti-inflammatory and antioxidant activities which are linked to its abundancy with polyphenols.

Essential oils of Psidium cattleianum Sabine leaves and flowers: Anti-inflammatory and cytotoxic activities

Introduction: Psidium cattleianum Sabine is a Brazilian native shrub cultivated for its edible fruit araçá (strawberry guava). P. cattleianum is recognized for health and food applications, although the essential oils (EOs) from the Egyptian inhabitant are not fully explored. The current study investigated the anti-inflammatory and cytotoxic activities of EOs from P. cattleianum leaves and flowers. Materials and methods: The EOs were obtained by three different methods viz; the conventional hydro-distillation, microwave assisted hydro-distillation, and supercritical fluid extraction, while their analysis was accomplished using GC/MS. The derived EOs were screened for their anti-inflammatory activity in the 5-lipoxygenase, COX-1, and COX-2 enzyme based assays, while the anticancer potential was deduced from MTT cytotoxic assay, cell cycle, and western blotting analysis. Results and discussion: Among other methods, supercritical fluid extraction offered the highest EO yield, 0.62% (leaves) and 1.4% (flowers). GC/MS identified β-caryophyllene and α-humulene in both organs with high but variable percentages. The leaves demonstrated strong activity in inhibiting the 5-lipoxygenase enzyme (IC50 2.38), while the flowers, in inhibiting COX-2 (IC50 2.575). Moreover, the leaves showed potent, selective cytotoxicity to MCF-7 cells (IC50 5.32) via apoptosis by modulating the p53/Bax/Bcl2 axis. The deduced activities are possible due to the synergism between the volatile components that endorses P. cattleianum leaves' EOs in the management of breast cancer and inflammatory disorders.

UHPLC-MS profiles and antidiarrheal activity of Quercus coccinea münchh. and Quercus robur L. employing in vivo technique

Introduction: Quercus L. genus (Oak) belongs to the family Fagaceae and their galls are used commercially in leather tanning, dyeing, and ink preparation. Several Quercus species were traditionally used to manage wound healing, acute diarrhea, hemorrhoid, and inflammatory diseases. The present study aims to investigate the phenolic content of the 80% aqueous methanol extract (AME) of Q. coccinea and Q. robur leaves as well as to assess their anti-diarrheal activity. Methods: Polyphenolic content of Q. coccinea and Q. robur AME were investigated using UHPLC/MS. The antidiarrheal potential of the obtained extracts was evaluated by conducting a castor oil-induced diarrhea in-vivo model. Result and Discussion: Twenty-five and twenty-six polyphenolic compounds were tentatively identified in Q. coccinea and Q. robur AME, respectively. The identified compounds are related to quercetin, kaempferol, isorhamnetin, and apigenin glycosides and their aglycones. In addition, hydrolyzable tannins, phenolic acid, phenyl propanoides derivatives, and cucurbitacin F were also identified in both species AME of Q. coccinea (250, 500, and 1000 mg/kg) exhibited a significant prolongation in the onset of diarrhea by 17.7 %, 42.6%, and 79.7% respectively while AME of Q. robur at the same doses significantly prolonged the onset of diarrhea by 38.6%, 77.3%, and 2.4 folds respectively as compared to the control. Moreover, the percentage of diarrheal inhibition of Q. coccinea was 23.8%, 28.57%, and 42,86% respectively, and for Q. robur 33.34%, 47.3%, and 57.14% respectively as compared to the control group. Both extracts significantly decreased the volume of intestinal fluid by 27%, 39.78%, and 50.1% for Q. coccinea respectively; and by 38.71%, 51.19%, and 60% for Q. robur respectively as compared to the control group. In addition, AME of Q. coccinea exhibited a peristaltic index of 53.48, 47.18, and 42.28 with significant inhibition of gastrointestinal transit by 18.98%, 28.53%, and 35.95 % respectively; while AME of Q. robur exhibited a peristaltic index of 47.71, 37, and 26.41 with significant inhibition of gastrointestinal transit by 27.72%, 43.89%, and 59.99% respectively as compared with the control group. Notably, Q. robur showed a better antidiarrheal effect in comparison with Q. coccinea and, the highest effect was observed for Q. robur at 1000 mg/kg as it was nonsignificant from the loperamide standard group in all measured parameters.

Melaleuca rugulosa (Link) Craven Tannins: Appraisal of anti-inflammatory, radical scavenging activities, and molecular modeling studies

ETHNOPHARMACOLOGICAL RELEVANCE

Genus Melaleuca or tea tree species are well known to be an important source of biological active oils and extracts. The biological significance appears in their usage for treatment of several clinical disorder owing to their traditional uses as anti-inflammatory, antibacterial, antifungal, and cytotoxic activities.

AIM OF THE STUDY

Our study aimed to investigate the metabolic profile of the M. rugulosa polyphenol-rich fraction along with determination of its anti-inflammatory potential, free radical scavenging and antiaging activities supported with virtual understanding of the mode of action using molecular modeling strategy.

MATERIALS AND METHODS

The anti-inflammatory activity of the phenolic rich fraction was investigated through measuring its inhibitory activity against inflammatory mediators viz tumor necrosing factor receptor-2 (TNF-α) and cyclooxygenases 1/2 (COX-1/2) in a cell free and cell-based assays. Moreover, the radical scavenging activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and β-carotene assays, while the antiaging activity in anti-elastase, anti-collagenase, and anti-tyrosinase inhibitory assays. Finally, the biological findings were supported with molecular docking study using MOE software.

RESULTS

The chromatographic purification of the polyphenol-rich fraction of Melaleuca rugulosa (Link) Craven afforded fourteen phytoconstituents (1-14). The anti-inflammatory gauging experiments demonstrated inhibition of inflammatory-linked enzymes COX-1/2 and the TNF-α at low μg/mL levels in the enzyme-based assays. Further investigation of the underlying mechanism was inferred from the quantification of protein levels and gene expression in the lipopolysaccharide (LPS)-activated murine macrophages (RAW264.7) in vitro model. The results revealed the reduction of protein synthesis of COX-1/2 and TNF-α with the down regulation of gene expression. The cell free in vitro radical scavenging assessment of the polyphenol-rich fraction revealed a significant DPPH reduction, peroxyl radicals scavenging, and β-carotene peroxidation inhibition. Besides, the polyphenol-rich fraction showed a considerable inhibition of the skin aging-related enzymes as elastase, collagenase, and tyrosinase. Ultimately, the computational molecular modelling studies uncovered the potential binding poses and relevant molecular interactions of the identified polyphenols with their targeted enzymes. Particularly, terflavin C (8) which showed a favorable binding pose at the elastase binding pocket, while rosmarinic acid (14) demonstrated the best binding pose at the COX-2 catalytic domain. In short, natural polyphenols are potential candidates for the management of free radicals, inflammation, and skin aging related conditions.

CONCLUSION

Natural polyphenols are potential candidates for the management of free radicals, inflammation, and skin aging related conditions.

Anti-prostate cancer metabolites from the soil-derived Aspergillus neoniveus

Prostate cancer (PCa) ranks as one of the most commonly diagnosed malignancies worldwide. Toxicity, lack of clinical efficacy, and development of resistance phenotypes are the main challenges in the control of prostate malignancies. Notably, castration-resistance prostate cancer (CRPCa) is a highly aggressive and metastatic phenotype of the disease with a poor prognosis and very limited therapeutic options. Herein, we report the isolation and genotypic identification of a soil-derived fungus Aspergillus neoniveus using the PCR-based internal transcribed spacer (ITS) region amplification approach. HPLC/MS investigation of the metabolic profile of the ethyl acetate extract from the fungal biomass revealed tentative identification of forty-five compounds belonging to various chemical classes including γ-butyrolactones, alkaloids, phenolics, and quinoids. Furthermore, the chromatographic purification of microbial extract enabled the identification of nervonic acid methyl ester (1) for the first time from endophytic fungi, as well as acetyl aszonalenin (2), and butyrolactone II (3) for the first time from A. neoniveus. The chemical frameworks of the isolated compounds were identified via extensive spectral analysis including 1 and 2D NMR and MS. The X-ray crystal structure and absolute configuration of acetyl aszonalenin (2) were also determined. Additionally, screening of in vitro anticancer activity of the fungal extract revealed its potential antiproliferative and anti-migratory activities against five different prostate cancer cells (PC3, PC-3M, DU-145, CWR-R1ca, and 22Rv1), including different cells with the castration-resistance phenotype. Moreover, the isolated metabolites significantly inhibited the proliferation, migration, and colonization of human prostate cancer cells at low micromolar levels, thus providing credence for future investigation of these metabolites in relevant anti-prostate cancer animal models. Furthermore, computational target prediction tools identified the cannabinoid G-protein coupled receptors type 1 (CB1) as a potential biological target mediating, at least in part, the anticancer effects of acetylaszonalenin (2). Moreover, molecular modeling and docking studies revealed a favorable binding pose at the CB1 receptor orthosteric ligand pocket aided by multiple polar and hydrophobic interactions with critical amino acids. In conclusion, the Aspergillus neoniveus-derived prenylated indole alkaloid acetylaszonalenin has promising anticancer activity and is amenable to further hit-to-lead optimization for the control of prostate malignancies via modulating CB1 receptors

Appraisal on the Wound Healing Potential of Deverra tortuosa DC. and Deverra triradiata Hochst Essential Oil Nanoemulsion Topical Preparation

Deverra tortuosa (Desf.) DC. and Deverra. triradiata Hochst. ex Bioss are perennial desert shrubs widely used traditionally for many purposes and they are characteristic for their essential oil. The objective of the present study was to investigate the in vivo wound healing activity of the essential oil (EO) of D. tortuosa and D. triradiata through their encapsulation into nanoemulsion. EO nanoemulsion was prepared using an aqueous phase titration method, and nanoemulsion zones were identified through the construction of phase diagrams. The EO was prepared by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and supercritical fluid extraction (SFE) and analyzed using GC/MS. D. tortuosa oil is rich in the non-oxygenated compound, representing 74.54, 73.02, and 41.19% in HD, MADH, and SFE, respectively, and sabinene represents the major monoterpene hydrocarbons. Moreover, D. triradiata is rich in oxygenated compounds being 69.77, 52.87, and 61.69% in HD, MADH, and SFE, respectively, with elemicin and myristicin as major phenylpropanoids. Topical application of the nanoemulsion of D. tortuosa and D. triradiata (1% or 2%) exhibited nearly 100% wound contraction and complete healing at day 16. Moreover, they exhibit significant antioxidant and anti-inflammatory effects and a significant increase in growth factors and hydroxyproline levels. Histopathological examination exhibited complete re-epithelialization accompanied by activated hair follicles and abundant collagen fibers, especially at a concentration of 2%. Therefore, the incorporation of the two Deverra species into nanoemulsion could professionally endorse different stages of wound healing.

Ethnopharmacological impact of Melaleuca rugulosa (Link) Craven leaves extract on liver inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Melaleuca species have been used by many ethnic communities for the management and treatment of several ailments as hemorrhoids, cough, skin infections, rheumatism, sore throat, pain, inflammation, and digestive system malfunctions. However, the detailed mechanistic pharmacological effect of Melaleuca rugulosa (Link) Craven leaves in the management of liver inflammation has not been yet addressed.

AIM OF THE STUDY

The present study aimed to evaluate the anti-inflammatory, antioxidant, and antiapoptotic capacities of the aqueous methanol extract of M. rugulosa leaves in relevance to their flavonoid content using an appropriate in vivo model.

MATERIALS AND METHODS

The aqueous methanol extract of M. rugulosa leaves was administered to the rats at three non-toxic doses (250, 500, and 1000 mg/kg) for seven days prior to the initiation of liver-injury induced by paracetamol (3 g/kg). Liver enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were evaluated in serum samples. The oxidative stress markers including reduced glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) levels as well as the inflammatory markers such as tumour necrosis factor-alpha (TNF-α) and nuclear factor-kappa B (NF-κB), were assessed in liver homogenate. The results were supported by histopathological and immuno-histochemical studies. The phytochemical investigation of the flavonoid-rich fraction of the aqueous methanol extract was accomplished using different chromatographic and spectroscopic techniques.

RESULTS

The aqueous methanol extract of M. rugulosa leaves showed a powerful hepatoprotective activity evidenced by the significant reduction of MDA and NO levels, as well as increasing GSH and catalase activity. Moreover, the extract exhibited anti-inflammatory and antiapoptotic activities witnessed by decreasing TNF-α, NF-κB, iNOS, p-JNK, caspase-3, BAX, and increasing Bcl-2 levels. Moreover, the pretreatment of rats with all doses of M. rugulosa leaves extract showed a significant decrease in liver weight/body weight (LW/BW) ratio, and total bilirubin induced by paracetamol. On the other hand, the chromatographic separation of the flavonoid-rich fraction afforded twenty known flavonoids namely; iso-orientin (1), orientin (2), isovitexin (3), vitexin (4), quercetin-3-O-β-D-glucuronid methyl ether (5), quercetin-3-O-β-D-mannuronpyranoside (6), isoquercetin (7), quercitrin (8), kaempferol-3-O-β-D-mannuronopyranoside (9), kaempferol-7-O-methyl ether-3-O-β-D-glucopyranoside (10), guaijaverin (11), avicularin (12), kaempferide-3-O-β-D-glucopyranoside (13), astragalin (14), afzelin (15), luteolin (16), apigenin (17), quercetin (18), kaempferol (19), and catechin (20).

CONCLUSION

The aqueous methanol extract of M. rugulosa leaves showed potential hepatoprotective, antioxidant, and anti-inflammatory activities against paracetamol-induced liver inflammation which is correlated at least in part to its considerable phenolic content.

Polyphenolic profile and ethno pharmacological activities of Callistemonsubulatus (Cheel) Craven leaves cultivated in Egypt

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Callistemon (syn. Melaleuca) of the myrtle family (Myrtaceae) has been documented as an integral part in the ethnobotanical system of the indigenous people of Australian mainland and many of its islands. Several Callistemons including the species subulatus were used by aboriginal Australians for making rafts, roofs for shelters, bandages, and food recipes, in addition to the management of wounds, infections, pain, cough, bronchitis, and gastrointestinal tract (GIT) disorders.

AIM OF THE STUDY

The current study is designed to document the therapeutic effect of the aqueous methanolic extract (AME) of C. sabulatus Chell (syn. M. sabulata) leaves in the management of diarrhea and pain. Also, its influence on additional pharmacological modalities that are related to oxidative stress just as skin aging. Ultimately, the polyphenolic profile of the extract is disclosed and correlated to the aforementioned bioactivities.

MATERIALS AND METHODS

The extract was fractionated using various chromatography techniques and the structures of the isolated compounds were determined based on their chemical and spectral data. The antioxidant activity was assessed using multiple models, including 2,2-diphenyl-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and β-carotene bleaching assays. The anti-skin aging effect was evaluated using different relevant enzymatic assays. The antinociceptive activity was investigated using acetic acid-induced writhing, hot plate test, and formalin-induced paw licking in mice models. The antidiarrheal activity was gauge using the castor oil induced diarrhea, enter pooling and gastrointestinal motility in vivo models.

RESULTS

Diverse polyphenols, including quercetin-3-O-β-D-glucuronopyranoside (1), kaempferol-3-O-β-D-glucuronopyranoside (2), strictinin (3), quercetin-3-O-(2``-O-galloyl)-β-D-glucuronopyranoside (4), afzelin (5), di-galloyl glucose (6), mono-galloyl glucose (7), acacetin (8), apigenin-6,7-dimethyl ether (9), kaempferol trimethyl ether (10), dimethoxy chrysin (11), quercetin (12), kaempferol (13), methyl gallate (14), and gallic acid (15) were identified. The extract exhibited as significant antioxidant activity even better than that of Trolox or BHT. Moreover, it exerts elastase, tyrosinase, and collagenase inhibition activities, in addition to the significant peripheral and central analgesic activity in a dose-dependent manner (P < 0.0001). In castor oil induced diarrhea model, AME significantly prolonged the diarrhea onset, decreased the frequency of defecation, and weight of feces. Likewise, it exhibited a significant reduction in the gastrointestinal motility in charcoal meal model (P < 0.0001) and a considerable inhibitory effect on gastrointestinal transit and peristaltic index with all investigated doses (P < 0.0001).

CONCLUSION

Ethnobotanicals are versatile resources for the management of various ailments by indigenous people and the experimental research is utmost to validate and uncover their pharmacological relevance. C. sabulatus leaves have strong antioxidant, analgesic, anti-skin aging, and antidiarrheal activities which are validated for the first time by various in vitro and in vivo models. The metabolic profile of the unprecedented AME of C. sabulatus leaves compromises a wide array of bioactive polyphenolic metabolites including, flavonoids, tannins, and phenolic acids that are correlated to the observed bioactivities. Altogether, ethnobotanicals with high and diverse contents of polyphenols are potential candidates for the management of various human aliments including neuropathies, GIT disorders, and skin aging conditions.

Cytotoxicity, Antimicrobial, and In Silico Studies of Secondary Metabolites From Aspergillus sp. Isolated From Tecoma stans (L.) Juss. Ex Kunth Leaves

Endophytes are prolific producers of privileged secondary metabolites with diverse therapeutic potential, although their anticancer and antimicrobial potential still have a room for further investigation. Herein, seven known secondary metabolites namely, arugosin C (1), ergosterol (2), iso-emericellin (3), sterigmatocystin (4), dihydrosterigmatocystin (5), versicolorin B (6), and diorcinol (7) were isolated from the rice culture of Aspergillus sp. retrieved from Tecoma stans (L.) Juss. ex Kunth leaves. Their anticancer and antimicrobial activities were evaluated in MTT and agar well diffusion assays, respectively. The cytotoxicity results showed that metabolite 3 displayed the best viability inhibition on the MCF-7 breast cancer cells with IC₅₀ = 225.21 µM, while 5 on the HepG2 hepatocellular carcinoma cells with IC₅₀ = 161.81 µM. 5 demonstrated a 60% apoptotic mode of cell death which is virtually correlated to its high docking affinity to Hsp90 ATP binding cleft (binding score −8.4 Kcal/mol). On the other side, metabolites 4 and 5 displayed promising antimicrobial activity especially on Pseudomonas aeruginosa with MIC = 125 μg/ml. The observed effect may be likely related to their excellent in silico inhibition of the bacterial DNA-gyrase kinase domain (binding score −10.28 Kcal/mol). To the best of our knowledge, this study is the first to report the promising cytotoxic and antibacterial activities of metabolites 3, 4, and 5 which needs further investigation and renovation to therapeutic leads.

Polyphenolic Profile of Callistemon viminalis Aerial Parts: Antioxidant, Anticancer and In Silico 5-LOX Inhibitory Evaluations

Five new compounds viz kaempferol 3-O-(4″-galloyl)-β-d-glucopyranosyl-(1‴→6″)-O-β-d-glucopyranoside (1), kaempferol 3-O-β-d-mannuronopyranoside (2), kaempferol 3-O-β-d-mannopyranoside (3), quercetin 3-O-β-d-mannuronopyranoside (4), 2, 3 (S)- hexahydroxydiphenoyl]-d-glucose (5) along with fifteen known compounds were isolated from 80% aqueous methanol extract (AME) of C. viminalis. AME and compounds exerted similar or better antioxidant activity to ascorbic acid using DPPH, O₂⁻, and NO inhibition methods. In addition, compounds 16, 4, and 7 showed cytotoxic activity against MCF-7 cell lines while 3, 7 and 16 exhibited strong activity against HepG2. An in silico analysis using molecular docking for polyphenolic compounds 2, 3, 7, 16 and 17 against human stable 5-LOX was performed and compared to that of ascorbic acid and quercetin. The binding mode as well as the enzyme-inhibitor interactions were evaluated. All compounds occupied the 5-LOX active site and showed binding affinity greater than ascorbic acid or quercetin. The data herein suggest that AME, a source of polyphenols, could be used against oxidative-stress-related disorders.

Pharmacological activity and flavonoids constituents of Artemisia judaica L aerial parts

ETHNO-PHARMACOLOGICAL RELEVANCE

Artemisia judaica L is an aromatic medicinal plant growing widely in Saint Katherine, Sinai, Egypt, and used in traditional medicine as a herbal remedy for antibacterial, anthelmintic, antidiabetic, analgesic and anti-inflammatory activities. Additionally, other Arabic regions commonly used it in their folk medicines for the treatment of fungal infections, atherosclerosis, cancer, diabetes, arthritis, and inflammatory-related diseases.

AIM OF THE STUDY

Based on the traditional medicinal uses of A. judaica, the present study was designed to validate some of the traditional uses as the analgesic, anti-inflammatory, antipyretic, hepatoprotective, antidiabetic, and antioxidant activities of 80% aqueous methanol extract (AME) of A. judaica aerial parts as well as isolation and identification of its flavonoid content.

MATERIALS AND METHODS

AME of A. judaica aerial parts was fractionated using column chromatography and the structures of the isolated compounds were established using different spectroscopic data. Analgesic activity was evaluated using acetic acid-induced writhing in mice; antipyretic activity was assessed using yeast suspension-induced hyperthermia in rats; anti-inflammatory activity was evaluated using carrageenan-induced paw edema; the hepatoprotective effect was studied by measuring liver enzymes in carbon tetrachloride(CCl₄)-induced hepatotoxicity rats while antidiabetic activity was estimated in alloxan hyperglycemia.

RESULTS

Eight flavone compounds namely luteolin 4' methyl ether 7-O-β-D-⁴C₁-glucopyranoside (1), 8-methoxyapigenin 7-O-β-D-⁴C₁-galactopyranoside (2), isovitexin (3), 8-methoxyluteolin 7-O-β-D-⁴C₁-glucopyranoside (4), diosmetin (5), cirsimaritin (6), luteolin (7), and apigenin (8) were identified from AME of A. judaica. The AME was found to be non-toxic to mice up to 5 g/kg b.w. Moreover, it exhibits significant analgesic antipyretic, anti-inflammatory, antidiabetic, hepatoprotective, and antioxidant activities in a dose-dependent manner.

CONCLUSION

The AME was nontoxic; it exhibits significant analgesic, antipyretic, anti-inflammatory, antidiabetic, hepatoprotective, and antioxidant activities. Moreover, the isolated flavone was identified from AME for the first time.

New phenolic compounds from Calothamnus quadrifidus R.Br. aerial parts and their antioxidant activity

Two new compounds calothphenone (1) and 6-methoxy kaempferol 3-O-(6″-E-p-coumaroyl)-β-d-glucopyranoside (6-methoxy tiliroside) (2) along with six known compounds viz gallic acid (3), methyl gallate (4), kaempferol 3-O-(6″-E-p-coumaroyl)-β-d-glucopyranoside (tiliroside) (5), castalagin (6), kaempferol (7) and quercetin (8) were isolated from the ethyl acetate fraction (EAF) of 80% aqueous methanol extract of Calothamnus quadrifidus aerial parts. Their structure was established based on different chemical and spectroscopic techniques (¹H-/¹³C-NMR and 2D NMR). Antioxidant activity for EAF and compounds 1, 2 and 5 was evaluated using DPPH, superoxide radical and nitric oxide (NO) inhibition methods. EAF exhibited strong activity to inhibit DPPH, superoxide and NO radicals. Moreover, all tested compounds demonstrated a close high ability to inhibit superoxide and NO radicals in comparison to ascorbic acid, but they exerted lower activity towards DPPH radical.[Figure: see text].

Antidiabetic and Antioxidant Effects of Acteoside from Jacaranda mimosifolia Family Biognoniaceae in Streptozotocin–Nicotinamide Induced Diabetes in Rats

BACKGROUND: Acteoside is a phenylethanoid compound isolated from Jacaranda mimosifolia D. Don leaves with a potential antidiabetic effect. OBJECTIVES: This study was designed to investigate the antidiabetic and antioxidant effects of acteoside in streptozotocin-nicotinamide (STZ-NA)-induced Type 2 diabetes in rats. METHODS: Diabetes was induced by intraperitoneal (i.p.) injection of a single dose of STZ (52.5 mg/kg), 15 min following i.p. administration of NA (25 mg/kg). Rats were divided into six groups; Group I: Normal rat group received the vehicle, Group II: Diabetic control group, and Groups III-IV: Diabetic rat groups were treated by either oral acteoside (10, 20, and 40 mg/kg) or pioglitazone (30 mg/kg) for 21 consecutive days. Biochemical parameters were assessed in the serum and liver homogenates. Examination of liver sections for histopathology was also carried out. RESULTS: Acteoside treated rats showed significant lower levels of blood glucose, glycosylated hemoglobin, total cholesterol, triglycerides, and increased serum insulin compared to control diabetic rats. Furthermore, acteoside treated rats, in comparison to the diabetic control, demonstrated significantly reduced malondialdehyde, increased reduced glutathione liver contents, and attenuated pathological alterations in the liver. These effects were comparable to those caused by the standard antidiabetic drug, pioglitazone. In vitro, acteoside scavenged stable free radical 1,1-diphenyl-2-picrylhydrazyl. CONCLUSION: Acteoside could be considered as a potential therapeutic agent for type 2 diabetes mellitus. However, studying further mechanisms underlying its antidiabetic effect is recommended.

New Apigenin Glycoside, Polyphenolic Constituents, Anti-inflammatory and Hepatoprotective Activities of Gaillardia grandiflora and Gaillardia pulchella Aerial Parts

BACKGROUND

Gaillardia grandiflora Hort. ex Van Houte and Gaillardia pulchella Foug are flowering plants widely cultivated in Egypt for their ornamental value. Previous reports demonstrated that sesquiterpene derivatives represent the major compounds in both species. Moreover, only few flavones were identified from genus Gaillardia and few studies on the cytotoxicity of G. pulchella were found.

AIM OF THE STUDY

Investigation of the phenolic constituents of the aerial parts of both species and evaluation of their anti-inflammatory and hepatoprotective activities.

MATERIALS AND METHODS

The 80% aqueous methanol extracts (AME) were prepared for both plants and evaluated for their biological activities. Phytochemical investigation of both extracts resulted in isolation of twelve compounds, which have been identified on the basis of ultraviolet, 1D and 2D nuclear magnetic resonance spectroscopy and negative ESI-MS.

RESULTS

The new 8-hydroxyapigenin 6-O-β-D-apiofuranosyl-(1'''→6'')-C-β-D-⁴C₁-glucopyranoside was isolated from G. grandiflora for the first time in nature, along with schaftoside, luteolin 6-C-β-D-⁴C₁-glucopyranoside 8-methyl ether, apigenin 6-C-β-D-⁴C₁-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin, as well as vicenin-2, vitexin, luteolin and apigenin, which were isolated from G. pulchella together with 6-methoxyluteolin. Furthermore, the AME of both species were found to be nontoxic to mice and exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner.

CONCLUSION

Current results shed light on the phenolic constituents of G. grandiflora and G. pulchella aerial parts and the safety of the AME of both species, in addition to their significant anti-inflammatory and hepatoprotective activities. Both plant species may be promising candidates for natural anti-inflammatory and hepatoprotective drugs.

SUMMARY

Phytochemical investigation of Gaillardia grandiflora and Gaillardia pulchella 80% aqueous methanol extracts of the aerial parts led to the isolation of twelve compoundsThe new compound 8-hydroxyapigenin 6-O-β-D-apiofuranosyl-(1''''→6'')-C-β-D-4C1-glucopyranoside was isolated from G. grandiflora for the first time in natureSchaftoside, luteolin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, apigenin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin were isolated from G. grandifloraVicenin-2, vitexin, luteolin, apigenin and 6-methoxyluteolin were isolated from G. pulchellaThe extracts of both species were nontoxic to mice up to 5 g/kg body weightBoth extracts exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner Abbreviations used: ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AME: The 80% aqueous methanol extract of G. grandiflora or G. pulchella aerial parts; AST: Aspartate aminotransferase; br d: Broad doublet; Comp-PC: Comparative paper chromatography; d: Doublet; 2D-PC: Two-dimensional paper chromatography; DMSO-d6: Deuterated dimethyl sulfoxide; G.: Gaillardia; GPx: Glutathione peroxidase; GRd: Glutathione reductase; GSH: glutathione; GST: Glutathione-S-transferase; J: Nuclear spin-spin coupling constant; m: Multiplet; [M-H]-: Molecular ion peak; MDA: Malondialdehyde; m/z: Mass/charge ratio; NO: Nitric oxide; p: Probability; PC: Paper chromatography; Rf: Retention flow; rpm: Rotation per minute; s: Singlet; SDE: The ethanol extract of Scoparia dulcis; SE: Standard error; SOD: Superoxide dismutase; TMS: Tetramethylsilane; λmax: Maximum fluorescence emission wavelength.

A Novel Phenylethanoid Dimer and Flavonoids from Jacaranda mimosaefolia

A novel phenylethanoid dimer, namely, jacraninoside A (1) and the five known constituents E/Z-acetoside (2), isoacetoside (3), cistanoside E (4), 6 '-acetylacetoside (5), and campneoside I (6) together with the seven flavonoids isoquercitrin (7), scutellarein 7-O-β -D-glucuronopyranoside methyl ester (8), apigenin 7-O-β -D-galacturonopyranoside (9), luteolin 7-O-β -D-glucuronopyranoside methyl ester (10), apigenin 7-O-β -D-glucuronopyranoside methyl ester (11), luteolin 7-O-β -Dglucopyranoside (12), and isovitexin (13) were isolated from the aqueous methanol extract of Jacaranda mimosaefolia D. Don. leaves. All known metabolites have been identified in this genus for the first time except for 2 and 12 which had been isolated once before from the leaves and twigs of Jacaranda mimosaefolia. Their structures were elucidated based on chemical evidences and spectroscopic analyses (1D and 2D NMR, HRMS ((-)-ESI)/MS, UV).

Spectroscopic Identifi cation of New Ellagitannins and a Trigalloylglucosylkaempferol from an Extract of Euphorbia cotinifolia L. with Antitumour and Antioxidant Activity

From an extract of leaves and small branches of Euphorbia cotinifolia L., 17 polyphenols were isolated including two new ellagitannins and a trigalloyl-glucosylkaempferol. Based on extensive spectral data (UV, ESI-MS, 1H NMR, DEPT and 1D/2D NMR) and chemical studies, their structures were characterized as 1-O-galloyl-3,6-hexahydroxydiphenoyl-DB1,4- glucopyranose (), 1-O-galloyl-3,6-valoneoyl-D-B1,4-glucopyranose (6), and kaempferol 3-O-(2”,3”,6”-tri-O-galloyl)-β-D-glucopyranoside (13). Biological evaluation indicated that the 80% aqueous methanol extract (AME), chloroform extract (CE), and some pure compounds have potent scavenging activity in the DPPH assay with SC50 values lower than that of ascorbic acid, especially 5, 7 - 9, and a mixture of hyperin 6”-gallate (11) and isoquercitrin 6”-gallate (12). Moreover, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assay, 6 and 8 exhibited the highest inhibition of human hepatocellular carcinoma cells (Hep-G2), while AME, CE, 5, 7, 9, and the mixture of 11 and 12 were found to be moderate growth inhibitors according to their IC50 values. In addition, AME, 5, and 8 exhibited significant antiproliferative activity against colon carcinoma cells (HCT-116); however, CE and the other examined compounds displayed moderate to low antitumour activity against HCT-116 cells

Spectroscopic identification of new ellagitannins and a trigalloyl-glucosylkaempferol from an extract of Euphorbia cotinifolia L. with antitumour and antioxidant activity

From an extract of leaves and small branches of Euphorbia cotinifolia L., 17 polyphenols were isolated including two new ellagitannins and a trigalloyl-glucosylkaempferol. Based on extensive spectral data (UV, ESI-MS, 1H NMR, DEPT and 1D/2D NMR) and chemical studies, their structures were characterized as 1-O-galloyl-3,6-hexahydroxydiphenoyl-D-B1,4-glucopyranose (5), 1-O-galloyl-3,6-valoneoyl-D-B1,4-glucopyranose (6), and kaempferol 3-O-(2",3",6"-tri-O-galloyl)-beta-D-glucopyranoside (13). Biological evaluation indicated that the 80% aqueous methanol extract (AME), chloroform extract (CE), and some pure compounds have potent scavenging activity in the DPPH assay with SC50 values lower than that of ascorbic acid, especially 5, 7-9, and a mixture of hyperin 6"-gallate (11) and isoquercitrin 6"-gallate (12). Moreover, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assay, 6 and 8 exhibited the highest inhibition of human hepatocellular carcinoma cells (Hep-G2), while AME, CE, 5, 7, 9, and the mixture of 11 and 12 were found to be moderate growth inhibitors according to their IC50 values. In addition, AME, 5, and 8 exhibited significant antiproliferative activity against colon carcinoma cells (HCT-116); however, CE and the other examined compounds displayed moderate to low antitumour activity against HCT-116 cells.

Phytoconstituents of Jatropha curcas L. leaves and their immunomodulatory activity on humoral and cell-mediated immune response in chicks

A novel biflavone di-C-glucoside, 6,6"-di-C-beta-D-glucopyranoside-methylene-(8,8")-biapigenin (1), was isolated from the leaves of Jatropha curcas L. (Euphorbiaceae), together with six known compounds; apigenin 7-O-beta-D-neohesperidoside (2), apigenin 7-O-beta-D-galactoside (3), orientin (4), vitexin (5), vicenin II (6), and apigenin (7). Their structures were determined on the basis of extensive chemical and spectroscopic analyses (UV, NMR and HRESI-MS). The immunomodulatory effect of an 80% aqueous methanol extract (AME) and compounds 1-5 (0.25 mg/kg body wt) to one-day-old specific pathogen-free (SPF) chicks was determined. Stimulation of both humoral and cell-mediated seroresponse was observed, especially those of AME and compound 1. Remarkable effective increases of the antibody titers, lymphocyte and macrophage cells, in blood were recorded. SPF chicks treated with the tested samples exhibited protection against Newcastle disease challenge virus after being vaccinated.

Polyphenolic profile and bioactivity study of Oenothera speciosa Nutt. aerial parts

Two new flavonol glycosides, myricetin 4'-O-alpha-L-rhamnopyranoside (1) and quercetin 3'-O-alpha-L-rhamnopyranoside (2), together with a novel biflavonol compound, speciin (3), as well as eleven phenolic metabolites, namely myricitrin (4), europetin 3-O-alpha-L-(1)C(4)-rhamnopyranoside (5), quercitrin (6), hyperin (7), rhamnetin 3-O-beta-galacto-pyranoside (8), caffeic acid (9), caffeic acid methyl ester (10), chlorogenic acid (11), chlorogenic acid methyl ester (12), gallic acid (13) and gallic acid methyl ester (14), were identified from the 80 % methanol extract of the aerial parts (leaves and stems) of Oenothera speciosa Nutt. (Onagraceae). In addition myricetin (15), quercetin (16) and ellagic acid (17) were identified from the chloroform extract. The structures were established depending on their chemical and physical analyses (UV, HR-ESIMS, 1D and 2D NMR). It was found that 80 % aqueous methanol extract of O. speciosa is non-toxic to mice up to 5 g kg(-1)b wt. The investigated extract exhibited significant antihyperglycaemic and anti-inflammatory activities in a dose dependant manner. Also, the 80 % methanol extract, myricitrin(4) and hyperin(7) showed potent antioxidant activity in vitro using 1,1-diphenyl 2-picryl hydrazyl (DPPH) radical assay.

Anticancer and antioxidant tannins from Pimenta dioica leaves

Two galloylglucosides, 6-hydroxy-eugenol 4-O-(6'-O-galloyl)-beta-D-4C1-glucopyranoside (4) and 3-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol-2-O-(2',6'-di-O-galloyl)-beta-D -4C1-glucopyranoside (7), and two C-glycosidic tannins, vascalaginone (10) and grandininol (14), together with fourteen known metabolites, gallic acid (1), methyl gallate (2), nilocitin (3), 1-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (5), 4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (6), 3,4,6-valoneoyl-(alpha/beta)-D-glucopyranose (8), pedunculagin (9), casuariin (11), castalagin (12), vascalagin (13), casuarinin (15), grandinin (16), methyl-flavogallonate (17) and ellagic acid (18), were identified from the leaves of Pimenta dioica (Merr.) L. (Myrtaceae) on the basis of their chemical and physicochemical analysis (UV, HRESI-MS, 1D and 2D NMR). It was found that 9 is the most cytotoxic compound against solid tumour cancer cells, the most potent scavenger against the artificial radical DPPH and physiological radicals including ROO*, OH*, and O2-*, and strongly inhibited the NO generation and induced the proliferation of T-lymphocytes and macrophages. On the other hand, 3 was the strongest NO inhibitor and 16 the highest stimulator for the proliferation of T-lymphocytes, while 10 was the most active inducer of macrophage proliferation.

Flavonoids and Triterpenoid Saponins from Pimenta dioica (Merr.) L

The defatted and desalted 80% methanolic extract of the leaves of Pimenta dioica (Mirr.) L. resulted in the isolation of three triterpenoid saponins, 23-hydroxy-3α-[( O-α-L-rhamnopyranosyl-(1→2)- O-α-L-arabinopyranosyl) oxy] olean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)- O-β-D-galactopyranosyl-(1→6)- O-β-D-galactopyranosyl ester (1), 2α,3α,23-trihydroxyolean-12-en-28-oic acid O-β-D-glucopyranosyl ester (2), and 2α,3α,23-trihydroxyolean-13(18)-en-28-oic acid O-β-D-glucopyranosyl ester (3), along with a novel dihydrokaempferol glucoside, namely, 3-carboxy-6,8-di- C-methyl-dihydrokaempferol 3- O-β-D-glucopyranoside (4), together with three known flavonoids, quercetin 3- O-β-D-glucuronopyranoside (5), quercitrin (6) and mernesitin (7), all for the first time from the genus Pimenta. The structures were identified on the basis of chemical and physicochemical analysis (UV, HRESI-MS, 1 and 2D NMR).

Antinociceptive and anti-inflammatory steroidal saponins from Dracaena ombet

Two new steroidal saponins, namely (25R)-5beta-spirostan-3-beta-ol 3-O-beta-D-galactopyranosyl-(1'''-->4'')-O-beta-D-galactopyranosyl-(1''-->3')-O-beta-D-glucopyranoside (2), and (25R)-5beta-spirostan-3-beta-ol 3-O-beta-D-galactopyranosyl-(1'''-->4'')-O-beta-D-glucopyranosyl-(1''-->3')-O-beta-D-glucopyranoside (3), together with six known constituents, have been isolated from the leaves of Dracaena ombet Kotschy & Peyr. (Dracaenaceae). The structures of the two saponins were established by chemical and physicochemical analyses, including FAB- and HR-ESI-MS and 2D NMR. The fraction rich in saponins showed significant analgesic and anti-inflammatory activities (at a high dose of 30 mg/kg b.w.) and non-significant antiulcer activities at the same doses.

Antioxidant galloylated flavonol glycosides from Calliandra haematocephala

Three new acylated quercetin rhamnosides have been isolated from the leaves and stem of Calliandra haematocephala Hassk. (Fabaceae) and their structures were established as quercitrin 2''-O-caffeate (1), quercitrin 3''-O-gallate (2) and quercitrin 2'',3''-di-O-gallate (3). Also, 17 known compounds were identified as gallic acid (4), methyl gallate (5), caffeic acid (6), myricitrin (7), quercitrin (8), myricetin 3-O-beta-D-4C1-glucopyranoside (9), afzelin (10), isoquercitrin (11), myricetin 3-O-(6''-O-galloyl)-beta-D-glucopyranoside (12), myricitrin 2''-O-gallate (13), quercitrin 2''-O-gallate (14), afzelin 2''-O-gallate (15), myricitrin 3''-O-gallate (16), afzelin 3''-O-gallate (17), 1,2,3,4,6-penta-O-galloyl-beta-D-4C1-glucopyranose (18), myricitrin 2'',3''-di-O-gallate (19), quercetin 3-O-methyl ether (20), for the first time from the genus Calliandra except for 6. Compounds 7, 8, 13, 14, 16 and 19 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical, superoxide anion generation and DPPH radical in comparison with that of quercetin as a positive control in vitro. Compounds 7 and 8 exhibited lethal effect towards brine shrimp Artemia salina.

Antioxidant flavonol glycosides from Schinus molle

Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

Phytochemical constituents and hepatoprotective activity of Viburnum tinus

From the leaves of Viburnum tinus L. (Adoxaceae) two acylated iridoid glucosides (viburtinoside A and B), a coumarin diglucoside scopoletin 7-O-beta-D-sophoroside and a natural occurred dinicotinic acid ester 2,6-di-C-methyl-nicotinic acid 3,5-diethyl ester were isolated. In addition to these, 10 known compounds were isolated, namely two bidesmosidic saponins, a hexamethoxy-flavone and five flavonol glycosides, as well as suspensolide A and oleanolic acid were isolated for the first time in this genus and species, respectively. The structures were determined mainly by spectroscopic methods (UV, IR, ESI-MS, 1H-, 13C NMR and DEPT). Toxicity of the investigated extract was determined (LD50=500 mg/kg). CCl4-induced hepatotoxicity has been evaluated in terms of the determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid peroxide and nitric oxide levels in serum and compared using adult male rats weighing 150-180 g. Their highly elevated levels were significantly reduced by treatment with the investigated aqueous methanol extract in dose-dependent manner.

Sablacaurin A and B, two 19-nor-3,4-seco-lanostane-type triterpenoids from Sabal causiarum and Sabal blackburniana, respectively

In search for bioactive compounds from Sabal species, sablacaurin A [25-ethyl,23-methyl-19-nor-24-methylene-3,4-seco-4(28)-lanosten-10,3-olide] and sablacaurin B [24-ethyl,24-methyl-19-nor-3,4-seco-4(28),25(26)-lanostadiene-10,3-olide], the first 19-nor lanostane derivatives of the 3,4-seco type with a spiro element, have been isolated from the leaves of Sabal causiarum and Sabal blackburniana respectively, together with the known squalene (S. blackburniana) and ss-sitosterol (S. causiarum). From leaves of Sabal peregrina, the known triterpenes 3-oxo-24-methylenecycloartane and 24-methylcycloart-25(26)-en-3-one were isolated. The structures of these compounds were established from spectroscopic studies.

Polyphenols of Melaleuca quinquenervia leaves--pharmacological studies of grandinin

Four polyphenolic acid derivatives and three ellagitannins were isolated from the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake for the first time. Their structures were elucidated as gallic acid (1), ellagic acid (2), 3-O-methylellagic acid (3), 3,4,3'-tri-O-methylellagic acid (4), 2,3-O-hexahydroxydiphenoyl-(alpha/beta)-D-(4)C(1)-glucopyranose (5), castalin (6) and grandinin (7) on the basis of chemical, mass spectrometric (-ve ESI-MS) and spectroscopic (UV, (1)H-, (13)C NMR, (1)H,(1)H-, (1)H,(13)C-COSY, (1)H,(1)H-TOCSY and HMBC) analyses. Grandinin (the major compound) showed radical scavenging properties by its reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical [EC(50) = 4.3 +/- 0.3 micro g mL(-1)]. It was found to be relatively nontoxic in mice [LD(50) = 316 mg Kg(-1) b.wt.]. It exhibited a significant dose-dependent (35-70 mg Kg(-1)) hypoglycemic effect by significantly reducing blood glucose level in basal condition and after heavy glucose load in normal mice. Moreover, it reduced the elevated blood glucose level in STZ-induced diabetic mice. In addition, grandinin reduced the elevated blood urea nitrogen and serum lipid peroxides in STZ-induced diabetic mice.

Polyphenolic constituents of Callistemon lanceolatus leaves

Two new flavonol glycosides, kaempferol 3-O-beta-D-galacturonopyranoside and quercetin 3-O-(2"-O-galloyl)-beta-D-glucoronopyranoside, were isolated, from leaves of Callistemon lanceolatus DC, as well as eighteen known polyphenols (phenolic acids, flavonoids and three tannins). All structures were established mainly on the basis of chemical and spectroscopic analysis (UV, 1D NMR and negative ESI-MS) and finally confirmed by 2D NMR experiments (HMQC and HMBC), in the case of flavonoid glycosides and tannins.

Pharmacologically active ellagitannins from Terminalia myriocarpa

A new ellagitannin, methyl (S)-flavogallonate (14) along with fourteen known compounds, gallic acid, methyl gallate, ethyl gallate, 2,3-di-O-[( S)-4,5,6,4',5',6'-hexahydroxybiphenyl-2,2'-diyldicarbonyl]-(alpha/beta)-D-glucopyranose (4), vitexin, isovitexin, orientin, iso-orientin, kaempferol 3-O-beta-D-rutinoside, rutin, neosaponarin, ellagic acid, flavogallonic acid (13), and (alpha/beta)-punicalagin (15) have been isolated from the leaves of Terminalia myriocarpa Heurck. Protective effect of the major and structurally related compounds 4, 13, 15 and the new compound 14 against CCl 4 -induced hepatotoxicity has been evaluated and compared, using adult male rats weighing 200-250 g. Serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lipid peroxide and nitric oxide production were significantly increased by administration of CCl 4 to rats and then reduced significantly only by treatment with compounds 4, 14 and 15 in a dose-dependent manner. Comparison of the protective properties of these compounds showed that compound 14 is more potent than compound 15 than 4 and that compound 13 has a non-significant effect at the used two dose levels.

Acylated flavonol glycosides from Eugenia jambolana leaves

Two acylated flavonol glycosides and 15 known polyphenols have been isolated and identified from the leaves of Eugenca jambolana Lam. The structures of the new compounds were identified as 3-O-(4"-O-acetyl)-alpha-L-rhamnopyranoside of mearnsetin (myricetin 4'-methyl ether) and myricetin 3-O-(4"-O-acetyl-2"-O-galloyl)-alpha-L-rhamnopyranoside. The complete structure elucidation of all isolated metabolites based on chemical and spectroscopic methods of analysis (UV, 1D and 2D NMR) as well as negative ESI-MS with and without CID in-source fragmentation.

Two new flavonol glycosides from leaves of Koelreuteria paniculata

Two new flavonol glycosides were isolated from dried leaves of Koelreuteria paniculata Laxm. (Sapindaceae) and characterized as 6,8-dihydroxy-afzelin and afzelin 3"-O-gallate, based on chemical and spectral evidences, in addition to nine known polyphenolic metabolites, including eight isolated for the first time from this species.

Flavonoids of Melaleuca quinquenervia

From the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake, the new flavonoid 5,7,3',4'-tetrahydroxyflavone 2'-O-beta-D-glucopyranuronide, as well as eight known flavonol glycosides have been isolated and characterized. The structures were established by chromatography, chemical degradation and UV spectroscopy and confirmed by ESI-MS and NMR spectroscopy. This is the first report on the isolation and identification of these flavonoids in the genus Melaleuca.